Answer:Self-fulfilling prophecy
Explanation:Self-fulfilling prophecy is a phenomenon in which one predict a certain outcome of a situation and when these expectations actual come true , they believe they came true because of their predictions but only because their action align with what they expected which made it come true.
Justin predicts that his girlfriend parents doesn't love him as a result he acts in a way that is hostile towards them which result to the parents seeing him as rude and his conclusion would be that he was right.